Boiler outlet fitting



Oct. 8, 1957 E. B. TIDD BOILER OUTLET FITTING 3 Sheets-Sheet 1 Filed June 2, 1954 Oct. 8, 1957 E. B. TIDD BOILER OUTLET FITTING 5 Sheets-Sheet 2 Filed June 2, 1954 Jnw/nfar' Ida/71K 224d 4?? 5 fli ar iu Oct. 8, 1957 E. B. TlDD 2,808,994

BOILER OUTLET FITTING Filed June 2, 1954 5 Sheets-Sheet 5 I72 i/n 071' 22 11/5123 Tia 4L nited States Patent Ofiice 2,808,994 l atented Get. 8, 1957 BOILER OUTLET FITTING Edwin B. Tidd, Mount Prospect, 11]., assignor to Bell & Gossett Company, Morton Grove, Ill., a corporation of Illinois Application June 2, 1954, Serial No. 433,950 15 Claims. (Cl. 237-56) My invention relates to fittings and is primarily concerned with an article that is constructed and arranged for attachment to hot Water boilers having side or end outlets for supplying hot water to a heating system and to segregate air released from the water in the boiler and to direct its collection in an expansion or compression tank.

Hot water boilers having side or end, as distinguished from top, outlets present a special problem with respect to separation of air liberated from the water in the boiler and the prevention of its movement to the radiators or other heating units in the system where its trapping would hinder normal circulation of the hot water. In heating systems of the forcibly circulated type for which this fitting is primarily intended, the boiler, by reason of its substantially larger size relative to the system piping, constitutes a relatively low velocity zone in which air bubbles released by the heat may travel upwardly for collection under the top wall of the boiler.

Where the supply line to the system is tapped into the top wall, the direction of the released air to the expansion tank and of substantially bubble free water to the radiators can be accomplished by the use of the apparatus and fittings disclosed in U. S. Letters Patent Nos. 2,395,697 and 2,500,621, but these devices are not suitable for side or end outlet boilers due to the closeness of the boiler outlet to the water line in the boiler as regards elevation.

It is therefore one object of my invention to devise a fitting common to a supply line at its side or end connection to the boiler and to the expansion tank and in which provision is made for directing to the supply line water that is substantially free from air bubbles and for directing the released air to the tank.

These and further objects will be set forth in the following specification, reference being had to the accompanying drawings, and the novel means by which said objects are etfectuated will be definitely pointed out in the claims.

In the drawings:

Fig. 1 is an elevation of a typical hot water, sectional boiler forming part of a closed, forcibly circulated, hot water heating system and showing the relation of the fitting thereto.

Fig. 2 is an enlarged, sectional elevation of the fitting and a part of the boiler as viewed in Fig. 1.

Fig. 3 is a plan view of the fitting looking in the direction of the arrow 3 in Fig. 2.

Fig. 4 is a fragmentary sectional elevation similar to Fig. 2, but employing a hot water tube that is straight throughout its length.

Fig. 5 is also a sectional elevation similar to Fig. 2 and in which the fitting incorporates a valve that is gravity actuated to closure and opened by pump pressure acting through the hot water tube.

Fig. 6 shows a further modification in which a dual passage fitting of relatively simple construction is attached to the side of a boiler.

Fig. 7 is a sectional elevation showing a further modification that is intended for gas fired boilers whose sections are tied together by relatively small nipples.

Referring to Fig. 1, the numeral 10 designates a hot water boiler of common type which includes, front, intermediate and rear sections 11, 12 and 13, respectively, that are appropriately tied together and between which circulatory connections are established by means of upper and lower nipples 14 and 15, respectively. The boiler may be fired in any of the usual Ways and the rear section is connected at its lower end to a return pipe 16 leading from the usual space heating elements (not shown) and included in this pipe is a motor driven pump 17 that is responsive in the well known manner to a room thermostat (not shown) when heat is required.

Referring to Fig. 2, a nipple 18 is threaded in the end face of the front section 11 at the elevation of the nipples 14 which have the same diameter as the nipple 18. My improved fitting 19 is mounted on the part of the nipple 18 which extends outwardly of the section 11 and the fitting includes a wall 20 that divides the interior thereof into a chamber 21 that communicates through the nipple 18 with the interior of the boiler, and a chamber 22 that communicates with one end of a supply pipe 23 carried by the top of the fitting and which leads to the space heating elements.

One end of a tube 24 is sealably mounted in the wall 20 and extends through and in eccentric relation to the nipple 18 in such a way that the tube is closer to the bottom than to the top of the nipple. The opposite end of the tube 24 extends within the section 11 and is bent downwardly at 25 so that its opening faces toward the bottom of the section 11. Also carried by the top of the fitting 19 is the lower end of a pipe 26 that communicates through a passage 27 in the fitting with the chamber 21 and the opposite end of the pipe 26 connects with an expansion tank 28.

When the heating system is first filled, air is trapped in the boiler 10 above a water line generally represented by the numeral 29 in Figs. 1 and 2 and which lies just above the nipples 14 and 18. When heat is applied to the boiler, whether or not the pump 17 is operating, air bubbles are released and collect at the top of the boiler and pressure variations in the system from time to time cause a fluctuation in the Water level 29. Whenever this level drops below the upper portion of the nipple 18, air may pass therethrough to the pipe 26 and expansion tank 28 and when the pump is running, substantially bubble free water flows through the tube 24 to the supply pipe 23. The latter result is due to the eccentric relation of the tube 24 to the nipple 18 and their substantial differences in diameters, the wall 20 and the bend 25. The wall 20 prevents air flow to the chamber 22 and the position of the tube 24 is such that it is always submerged in water. As an ancillary feature, the downward facing of the open end of the bend 25, i. e., away from the level 29 or any variation thereof, insures that, when the pump is running, there will not be any local vortex action or depression of the level 29 which might otherwise draw air into the tube 24.

In Fig. 4 is illustrated a variant form of the fitting which dilfers from that shown in Fig. 2 only in the use of a completely straight tube 30 in place of the tube 24. Otherwise, the several parts are identical with those illustrated in Fig. 2 and denoted by the same numerals. The tube 30 is located in the same eccentric relation to the nipple 18 as is the tube 24 and its inlet end may be bias cut at 31 to facilitate flow of the hot Water to the tube. This arrangement will provide some separation of air from the water, but is not as efiicient as that shown in Fig. 2.

In Fig. 5 is shown a further modification in which the fitting is modified to include a flow control valve that opens when pump pressure is effective in the hot water tube. Certain parts are identical with those shown in Fig. 2 and are denoted by the same numerals.

The fitting in this instance is indicated by the numeral 32 and, as in Fig. 2, it is mounted on the nipple 18. The interior of the fitting 32 is interiorly divided by a wall including a horizontal portion 33 and a vertical portion 34. The latter wall portion forms one boundary of a chamber 35 that communicates through the nipple 18 with the interior of the boiler and also through the pipe 26 with the expansion tank 28. A hollow, cylindrical cage 36 extends upwardly through and in sealing relation to the bottom wall 37 of the fitting 32 and its upper end extends through and in sealing relation to the wall portion 33. The annular wall of the cage 36 is suitably apertured at 38 between the fitting walls 33 and 37 so that the interior of the indicated part of the cage is always in communication with a fitting chamber 39 included between the latter fitting walls and with the discharge end of the tube 24 which is carried by the wall portion 34 and is eccentrically related to the tube 18 in the same manner as heretofore described.

A seat ring 40 is press fitted in the upper end of the cage 36 and operably related to the ring is a valve disk 41 which includes depending fingers 42 which have guiding relation to a stem 43 that extends downwardly through and in threaded relation to the closed lower end of the cage 36 and outwardly thereof has afiixed thereto a handle 44. When the pump 17 is operating, the pressure which is effective in the tube 24 raises the valve disk 41 so that hot water may flow through the supply pipe 23. The opening movement of the valve disk 41, is limited by engagement of the fingers 42 with a spring ring 45 recessed in the stem 43.

The air separating action of the Fig. control is identical with the other modifications and may also employ the straight hot water tube 30 as a substitute for the tube 24. Its important feature is the inclusion of the pump actuated valve disk 41 and its relation to the hot water pipe 24, the interior of the cage 36 being in efiect a continuation of the latter pipe so that air separation occurs whether the valve disk 41 is open or closed.

The modification diagrammatically illustrated in Fig. 6 embodies the idea in a relatiively simpler structure. A fitting 46 having any external shape is suitably attached to an end or side of the boiler and includes upper and lower, horizontal passages 47 and 48, the top of the former passage being about at the same elevation as the water level 29 as heretofore defined. The passage 47 communicates with a pipe 49 leading to the expansion tank 28 while the passage 48 communicates with the hot water tube 30 which extends eccentrically through one or more nipples 50 connectingthe boiler sections as discussed for Fig. 4, and with a supply pipe 51 leading to the space heating units. The operation of this modification is identical with those heretofore described and the tube 24 may be substituted for the tube 30 if desired.

Sectional gas fired boilers of the smaller type, that is, those in which the sections are connected by nipples having a diameter of two inches or less, present a special problem with respect to insuring a separation of air bubbles from the water at the upper portion of the boiler. Such an arrangement is shown in Fig. 7 to which reference will now be made.

A fitting 52 is mounted on a nipple 53 which is carried by an end section of a boiler 54 and is located close to the top thereof in the same manner as the nipple 18. The nipple 53 constitutes what would otherwise be the normal outlet port of a small size, side opening, gas fired boiler and it and the nipples 55, which connect the intermediate boiler sections, have the same diameter, namely, two inches or less. A wall 56 internally divides the fitting 52 into a chamber 57 which communicates through a pipe 58 with the heating elements of the associated heating system and into a chamber 59 which communicates through the nipple 53 with the boiler 54.

One end of a straight, hot water tube 60 extends through the wall 56 in communication with the chamber 57 and the oppoiste end extends concentrically through and spaced from the nipple 53 and may also extend in the same way partially or completely through a nipple as shown. The inner or boiler end of the tube is closed by a plug 61 and the lower portion of the tube, i. e., in a direction facing the bottom of the boiler, is provided with an opening, or as shown in Fig. 7 with a plurality of openings 62 spaced therealong for a purpose presently explained.

In operation, hot water generally free of air bubbles flows through the openings 62 into the tube 60 and thence to the heating elements, while the liberated air passes through the nipple 53 above the tube and thence to a pipe 63 carried by the fitting 52 and leading to the expansion tank 28.

The purpose of the openings 62 is to insure a sufiiciently low velocity of the water in the region of the tube 60 so that the air bubbles will separate from the water. If the openings 62 were not provided and the plug 61 removed, it will be apparent that, due to the reduced diameter of the tube 60 relative to the transverse sectional area of a boiler section, the water would begin accelerating as it approached the assumed open end of the tube 60 and the air bubbles would not have time to separate from the water. The openings 62 slow down this tendency of the water to accelerate in the region of the tube 60 since their total area is in excess of the flow area of the tube and this area may be varied to suit different conditions. One opening or more than one opening may be used so long as the above flow area relation is maintained. The water flow immediately adjacent to and in approaching relation to the openings 62 should not be in excess of 7 ins./sec. as this and any lower rate enables the air bubbles to readily free themselves from the moving water.

It will be understood that the attachment of any of the above fittings to the front end of the boiler is not restrictive, but covers broadly the securement to any vertical boundary of the boiler whether end or side, in contradistinction to the common, horizontal top wall. Further, the invention is not restricted to sectional boilers, but may be used with boilers of any type and is also not restricted to heating systems of the forcibly circulated type, but may be employed with thermogravitational systems. In all of the above modifications, the hot water tube may extend through more than one nipple in the boiler and may be either eccentric or concentric with the nipple or nipples. The former is preferred where possible as it insures better air separation. Likewise, the flow control valve shown in Fig. 5 may be used with any of the other modifications. In Fig. 6, the fitting 46 may be omitted if desired and, in this event, the hot water tube 30 would extend through the boiler side wall for connection with the supply pipe 51, while the passage 47 would merely extend through this side wall above the tube 30 for connection with the expansion tank 28.

I claim:

1. A fitting for a hot water boiler having an outlet in a side wall thereof adjacent the top including first and second chambers, the first chamber being connectible to space heating elements and the second chamber providing communication between an expansion tank and the boiler outlet, and generally horizontal pipe means having a diameter substantially less'than, and extending through, said outlet and providing a space therebetween, said pipe means providing communication between said boiler and the first chamber, and the space between said pipe means and outlet providing communication between said second chamber and the upper part of said boiler.

2. A fitting for a hot water boiler having an outlet in a side wall adjacent the top thereof including first and second chambers, the first chamber being connectible to spaceheating elements and the second chamber providing communication between an expansion tank and the boiler outlet, and generally horizontal pipe means having a diameter substantially less than and extending through the outlet adjacent the lower part thereof and communicable With the first chamber and the boiler.

3. A fitting for a hot water boiler having an outlet in a side wall adjacent the top thereof including first and second chambers, the first chamber being connectible to space heating elements and the second chamber providing communication between an expansion tank and the boiler outlet, and generally horizontal pipe means extending through the outlet and communicable with the first chamber and the boiler, the boiler end of the pipe means being bent to face towards the bottom of the boiler.

4. A fitting for a hot water boiler having an outlet in a side wall adjacent the top thereof including first and second chambers, the first chamber being connectible to space heating elements and the second chamber providing communication between the boiler outlet and an expansion tank, and generally horizontal pipe means having a diameter substantially less than and extending through the outlet adjacent the lower part thereof and communicable with the first chamber and the boiler, the boiler end of the pipe means being bent to face towards the bottom of the boiler.

5. A device for facilitating the supply of substantially air bubble free water from a hot water boiler having an outlet in a side wall adjacent the top thereof comprising a nipple mounted horizontally in the outlet, and a fitting carried by the nipple and interiorly divided into first and second chambers, the first chamber being connectible to space heating elements and the second chamber being located adjacent the delivery end of the nipple and providing communication through the nipple between the boiler and an expansion tank, and a generally horizontal tube having a diameter substantially less than and extending through the nipple adjacent the lower part thereof and communicable with the first chamber and the boiler.

6. A device for facilitating the supply of substantially air bubble free water from a hot water boiler having an outlet in a side wall adjacent the top thereof comprising a nipple mounted horizontally in the outlet, and a fitting carried by the nipple and interiorly divided into first and second chambers, the first chamber being connectible to space heating elements and the second chamber being located adjacent the delivery end of the nipple and providing communication through the nipple between the boiler and an expansion tank, and a generally horizontal tube having a diameter substantially less than and extending through the nipple adjacent the lower part thereof and communicable with the first chamber and the boiler, the boiler end of the tube being bent to face towards the bottom of the boiler.

7. In a hot water heating system, the combination of a hot water boiler having a horizontal axis outlet in a side wall adjacent the top thereof, an expansion tank, and a fitting operably related to the outlet and including first and second chambers, the first chamber being connectible to space heating elements and the second chamber providing communication between the tank and the boiler outlet, and horizontal pipe means having a diameter substantially less than and extending through the outlet adjacent the lower part thereof and communicable with the first chamber and the boiler.

8. In a hot water heating system, the combination of a hot water boiler having a horizontal axis outlet in a side wall adjacent the top thereof, an expansion tank, and a fitting operably related to the outlet and including first and second chambers, the first chamber being connectible to space heating elements and the second chamber providing communication between the tank and the boiler outlet, and horizontal pipe means extending through the outlet and communicable with the first chamber and the boiler, the boiler end of the pipe means being bent to face towards the bottom of the boiler.

9. In a hot water heating system, the combination of a hot water boiler having a horizontal axis outlet in a side wall adjacent the top thereof, an expansion tank, a nipple mounted in the outlet, and a fitting carried by the nipple and interiorly divided into first and second chambers, the first chamber being connectible to space heating elements and the second chamber being located adjacent the delivery end of the nipple and providing communication through the nipple between the boiler and the tank, and a horizontal tube having a diameter substantially less than and extending through the nipple adjacent the lower part thereof and communicable with the first chamber and the boiler.

10. A fitting for a hot water boiler having an outlet in a side wall thereof adjacent to the top of the boiler, said fitting being adapted to be mounted on said boiler adjacent said outlet and having a first chamber connectible to space heating elements and a second chamber providing communication between an expansion tank and said boiler outlet, said fitting having a wall partially defining said first and second chambers and having an opening therein facing said boiler outlet, and generally horizontal pipe means having a diameter substantially less than said outlet, tightly secured in said wall opening and projecting outwardly therefrom through said second chamber and the boiler outlet into the interior of the boiler, and leaving a space between said pipe means and the upper part of said outlet thereby providing communication between said second chamber and the upper part of said boiler.

11. A device for facilitating the supply of substantially air bubble free water from a hot water boiler having a horizontal axis outlet in a side wall adjacent the top thereof comprising a nipple for mounting horizontally in the outlet, a fitting carried by the nipple and interiorly divided into first and second chambers, the first chamber being connectible to space heating elements and the second chamber being located adjacent the delivery end of the nipple and providing communication through the nipple between the boiler and an expansion tank, and a generally horizontal tube having a diameter substantially less than and extending eccentrically through the nipple adjacent the lower part thereof and communicable with the first chamber and the boiler.

12. In a hot water heating 5731mm including a circulating pump, an expansion tank and a boiler having a horizontal axis outlet in a side wall adjacent the top thereof, a nipple mounted in the outlet with its axis horizontal, a fitting carried by the nipple and internally divided by a wall including a vertical axis opening therethrough into a first chamber connectible to radiating elements and a second chamber providing communication between the tank and boiler through the nipple, a valve seat carried by the wall around the opening, a flow control valve operably related to the seat and responsive to pump operation for raising to an open position and closed by gravity, and a horizontal water tube extending eccentrically through and adjacent the lower portion of the nipple into the boiler and having its delivery end mounted in another part of the wall adjacent the inlet side of the valve.

13. A fitting as set forth in claim 1 in which said pipe means extends into the boiler and has an end wall closing the boiler end of the same, said pipe means also having one or more openings along the lower margin thereof to provide an inlet area for said pipe means greater than its cross-sectional area.

14. A fitting as set forth in claim 1 in which said pipe means extends into the boiler and has a downwardly facing opening within the boiler, with the space above said pipe means and between said pipe means and outlet providing communication between said second chamber and the upper part of said boiler.

15. In a hot water heating system, the combination of a hot water boiler having a horizontal axis outlet in a side wall adjacent the top thereof, an expansion tank,

a nipple mounted in the outlet, and a fitting carried by the nipple and interiorly divided into first and second chambers, the first chamber being, connectible to space heating elements and the second chamber being located adjacent the delivery end of the nipple and providing communication through the nipple between the boiler and the tank, and a horizontal tube having a diameter substantially less than and extending through the nipple providing communication between said first chamber and the boiler, said tube being spaced from the upper part of said ReferencesCited in the file of this patent UNITED STATES PATENTS Tidd -Feb. 26, 1946 Tidd Mar. 14, 1950 OTHER REFERENCES Trane News, volume 7, November 15, 1947, page 5, published by the Trane Company, La Crosse, Wisconsin. 

